You can create some beautiful patterns and textures by stamping leather, but there are only so many options for pre-made leather stamps. I was excited by the idea of having full creative control over my leather projects with my own custom designed stamps, and I wanted to see if I could do it with 3D printing.
The stamps I ended up creating were simple to design and they worked surprisingly well. They might not have quite the durability or definition that metal stamps do, but they still created some great patterns. I now have a million more ideas for interesting ways to use this technique, and I think it has the potential to create some very unique designs that differ from the familiar leatherworking aesthetic. This would also be a great way to add a logo stamp to personalize your designs if you are creating leather pieces to sell.
Step 1: Choose Your Material
Leather stamps need to be able to withstand a good amount of force and pressure, so creating them out of the right material is important.
At the Pier 9 studio we are lucky enough to have amazing Objet Connex 3D printers at our disposal. They are UV cure resin printers that print at a very high resolution in a few different materials. I chose to print my stamps in a hard 'ABS like' material because it was supposedly the strongest. Even so, I was skeptical that it would hold up to the stamping process, but so far so good!
I haven't tried printing in any other materials yet, but I doubt most other 3D print materials would be hard or strong enough. If you don't have access to an Objet you can send your stamp models to a printing service like Shapeways or Fathom. I would recommend talking to these services to determine which of their materials will work best for this purpose. Getting your shapes created with DMLS (direct metal laser sintering), which both of these printing services offer, would probably work even better.
Step 2: What You Need
To Design Your Stamps
- A Computer with a 3D modeling program - I used Autodesk Fusion 360
-Inspiration for your stamp design - photos of interesting patterns, physical objects, a sketch, or just an idea
-A ruler to give you a sense of scale while you're modeling
To Assemble Your Stamps
-A few short steel or aluminum rods about 5-6" long and about 1/2" in diameter (hardwood dowels might be strong enough as well)
-A strong two part epoxy
-Clamps or another means of holding your rods upright
-Gloves, a dish to mix your epoxy and a stirring stick
-Leather you want to create a pattern on - this needs to be a veg tanned leather thick enough to stamp like these
-A wooden, plastic or rawhide mallet
-A quartz slab or very hard surface as a base for stamping
-A softer board to go over the quartz - this will help prevent your stamps from breaking
-Water and a sponge
Step 3: Design Your Stamps
I designed 3 different stamp patterns for this experiment:
-A geometric stamp that I thought would look good stamped in a grid
-A stamp loosely based on a circuit board for more random pattern creation
-A faceted stamp that would create a simple interesting texture
I created the first two by finding images I liked, importing them into Fusion as canvases and sketching over them. I then extruded these sketches to a height of about 2-3mm and added details. In my first iteration, I left the top surfaces of the stamps fairly flat, but I found that chamfering the edges so they came to more of a point at the top helped the pattern have better definition when stamped.
I created the faceted stamp by making simple pyramid shapes in Fusion and putting them together. My first version of this stamp had too much relief, so that when it was stamped, only the very tips of the pyramids made imprints in the leather. I fixed this by playing with the scale in the Z axis.
By varying the depth of features in your stamps, you can create some difference in line weight, relief and shading, but this will only work within a very small range of about 2mm or less.
I also kept my stamps between about 2 and 3 centimeters across and printed some in different scales to see what looked good. I think you could potentially go bigger, but eventually you won't be able to exert enough pressure with a hammer to make a good impression with a large stamp.
To finish my stamps, I gave them each a solid base about 5mm thick. I cropped the profile of the bases roughly around the shape of my designs to make it easy to see when you are stamping and line up your stamps. I also cut out a socket on the underside of each stamp. I made this socket the diameter of my aluminum rods and about 2mm deep. This will help hold the rods in place on the stamps.
Step 4: Print Your Stamps
To print my stamps I exported them as STLs and loaded them into the Objet print software.
The Objet printers give you the option to print in 'glossy' or 'matte' finish. I chose glossy because it left the top surface of my stamps free of support material and gave them better definition.
These 5 stamps took about an hour to print.
Step 5: Assembling Your Stamps
Once your stamps are printed you can attach them to the rods you will use to hammer your design... but you don't have to.
I didn't have enough rods for all my stamps, so I left some of them separate and just placed a rod over them every time I wanted to hammer a stamp. It was slightly less convenient, but seemed to work just as well, especially for the larger stamps. Your choice.
To attach the rods, first make sure they are cut into 5-6" lengths. I used a cold metal saw to cut my aluminum rod, and then filed away the sharp burrs with a metal hand file.
I used clamps to fix my rod lengths in a vertical position for easy gluing.
Wearing gloves, I squeezed equal parts of my two part epoxy into a cup and mixed them together.
I applied a small amount of epoxy to the socket in the base of each stamp and stuck them to the ends of each rod. After about 10 minutes they were ready!
Step 6: Stamping!
I recommend testing your stamps before stamping them on anything important.
First assemble a good stamping surface. Do this by placing your poundo board over your marble or other hard surface.
Now 'case' your leather by applying water to both sides with a sponge. You want it to be damp, not soaked. Leather too dry will be hard to stamp, leather too wet won't hold the stamping patterns as well. It is better not to use a metal container for your water, as it can cause the leather to discolor. Wait a few minutes until your leather has gone back to its original color to begin stamping.
When you are ready to stamp, place your stamp on the leather and hold it down firmly (I found it was best to hold towards the middle of the metal rod and rest the heel of my hand on the board for a firm grip). Take you mallet and strike the end of your metal rod firmly. One firm strike works best. Striking more than once risks making the stamp bounce out of place and create a double image.
To use your unattached stamps, just place a metal rod in the socket on the back of the stamp and pound the same way.
If your leather starts to dry out while stamping, re-wet the whole thing with a sponge.
Try arranging your stamps in different ways to create textures and patterns. Lightly tracing a grid on your leather beforehand can help you create an even all-over pattern.
Step 7: Adding Finish to Your Leather
Treating your leather with dye or stain after stamping it can help bring out your patterns in an interesting way. Also, sealing veg tanned leather is a good idea if you want it to be durable and water resistant.
I used Tandy's Eco-Flo leather dye to dye my leather, and Eco-Flo Satin Shene to seal it.
Dye can be applied with a brush, a sponge or a rag. It can also be diluted to get lighter colors. You can find a detailed description of leather dying techniques in this excellent Instructable by jessyratfink.
After your leather is dyed to your liking, let it dry completely before sealing. I applied my Satin Shene with a slightly damp sponge. I gave it two coats, letting it dry in between.
Some dyes and leathers will interact differently. I had a hard time getting an even coat with the brown dye I tried and wasn't too happy with the final result, but loved the effect of the black and red. I think this may have had more to do with the type of leather I used with each stamp than the dye itself.
Step 8: Make More Things!
Now that I know this technique can achieve good results, I'm excited to apply it to different projects.
Custom stamps would be perfect for adding patterns to belts, bags, wallets, and all kinds of other leather work projects. Stamps created with a company name or logo could be a great way to make your mark on hand made designs.
Also, a lot of tooled leatherwork designs get their character from the tools used to detail the patterns, and being able to supplement my library of Tandy tools with my own custom textures and patterns opens up even more aesthetic possibilities.